Nearly 500,000 adolescents between the ages of 15 and 19 years gave birth in the United States in 1998. Many health and social issues surround these mothers and their infants, including the lower likelihood that they will initiate breastfeeding and, if initiated, do so for a shorter time than their adult counterparts. Given the significant health and social benefits of breastfeeding for infants and mothers, as recognized by the Healthy People 2010 objectives, interventions for this population are needed. Drawing on the Theory of Planned Behavior, the overall objective of the proposed study is to test developmentally sensitive interventions to enhance breastfeeding decision-making and increase the initiation and duration of breastfeeding among disadvantaged adolescent mothers. A randomized clinical trial will test the effects of a lactation consultant-peer counselor team. Experimental, attention control, and usual care control groups will be used to test two primary hypotheses: a) that the prenatal and in-hospital experimental interventions (Phase I) will result in a higher incidence of breastfeeding initiation at hospital discharge; and b) that those in the experimental group will breastfeed for longer durations than those in the attention control and usual care groups. At hospital discharge, the breastfeeding mothers in the experimental and attention control groups will be randomly assigned to receive the continued intervention/attention (Phase II) for four weeks. Differences in breastfeeding duration between experimental group subjects receiving only the Phase I components and those who receive both Phase I and II components will be examined to determine if the total intervention is needed to extend duration of breastfeeding in this disadvantaged population who are at high risk for early weaning. This is the first large-scale trial targeted at disadvantaged adolescents to improve breastfeeding outcomes and has the potential to positively enhance both the adolescent mothers' and their children's health.